Manufacturers and designers of drive systems are continually looking for ways to increase storage capacity while maintaining specific form factors for drive designs. There is a strong market for HGA (Head Gimbal Assembly) options that would allow decreased disk-to-disk spacing in the hard disk stack.
These manufacturers and designers are also searching for ways to increase yields through the drive manufacturing process and to increase product reliability. One option that many drive designers are using is to add a lifting mechanism to dynamically lift and lower the transducer head toward and away from the disk. The use of lifting mechanisms reduces wear on the HGA and on the disk during start-up and stop. A lifter thus adds reliability to the drive. Lifting devices are also used to hold the transducer head away from the disk during drive assembly. With increasingly closer disk spacing, there is very little clearance for lifters and for suspension clearance. There is also a potential for defects to occur if the lifter contacts the disk or if the transducer head is not properly lowered onto the disk.
The present invention provides a new load beam/HGA concept that offers:
Significantly diminished disk-to-disk spacing.
Simplified lifting method requiring only a single lifter extension for a paired set of HGAs attached to the same rigid actuator arm. The lifter raises or lifts each suspension away from its respective disk by entering between the two suspensions attached to the same rigid actuator arm.
Improved resonance characteristics due to the use of upright rails on the suspension.
Other workers in this field have proposed different types of staggered placement of HGAs to provide decreased disk-to-disk spacing. For example, U.S. Pat. No. 4,937,693, assigned to Hewlett-Packard Co., describes HGAs mounted in circumferentially spaced pairs on individual projections of a rotatable actuator, with the active faces of the heads pointing in opposite directions. This Hewlett-Packard patent and the present invention both effectively offer significant lowering of disk spacing and both position the transducer heads so that they are not one above the other in the head stack. However, the present invention allows both suspensions and their attached heads to be mounted in a direct line from the gap of the heads to the pivot of the E-block assembly. This configuration offers the ability to design for lower mass and inertia of the actuator assembly. Also, the design of the Hewlett-Packard patent requires the transducer heads to be mounted 90.degree. to the load beam and, if the transducer heads are mounted in line with the load beam, significant disk surface can not be utilized.
U.S. Pat. No. 4,443,824, assigned to IBM, describes a rigid actuator arm formed with exterior parallel arms supporting two transverse bridge elements spaced along the length of the arms so that each bridge supports two opposed load beams each provided with a magnetic transducer transducer head.
Current lower mass and inertia actuator designs require less power, offer better head positioning accuracy and faster access capabilities. The mounting of the suspensions in line with the pivot of the actuator and using rotary actuation is currently the most common way of configuring the actuator relative to the disks. Thus, the retro fit of the concept of the present invention requires significantly less drive design changes and allows the use of traditional form factors for drives with existing rotary actuator designs. The concept of the present invention permits the transducer head to be attached in line with the load beam, which is most common for current suspension/flexure designs.
A lifting mechanism can easily be implemented into the design of the present inventive suspension. The lift mechanism may be a stationary comb to which the present inventive actuator/suspension configuration can access directly as the actuator is moved toward the outer edge of the disk. The lift mechanism requires only one prong per paired suspension. By having paired suspensions lifted at the same time and on the same position of the comb ramp, the dynamic lifting and loading of the heads to the disk is uniform and consistent.